Interleukin-4 (IL-4) is a protein which affects a broad spectrum of hematopoietic cells [Strober et al., Pediatr. Res. 24:549 (1988)]. IL-4 enhances a number of activities including macrophage function, IgG and IgE production, and the proliferation of immunoglobulin-stimulated B cells, antigen-stimulated T cells and erythropoietin-stimulated red blood cell progenitors. It also increases the proliferation of IL-3-stimulated mast cells.
Together with IgE, mast cells play a central role in allergic reactions. Mast cells are granule-containing connective tissue cells which are located proximally to capillaries throughout the body, with especially high concentrations in the lungs, skin and gastrointestinal and genitourinary tracts. Following exposure to an antigenic substance, mast cells degranulate and release chemical mediators such as histamine, serotonin, heparin, prostaglandins etc. to produce an allergic reaction.
Because of the stimulatory effects of IL-4 on IgE production and mast cell proliferation, an antagonist of IL-4 may be useful for the treatment of allergies by decreasing mast cell growth and IgE production.
Some investigators have used antibodies to antagonize the biological activity of IL-4. For example, Finkelman et al. [Proc. Natl. Acad. Sci. USA 83:9675 (1986)] used a monoclonal antibody against BSF-1 (now called IL-4) to inhibit IL-4-induced production of IgE in mice infected with the nematode parasite Nippostrongylus brasiliensis or injected with a purified goat antibody to mouse IgD. Both treatments were known to stimulate IgE production; the latter treatment was also known to stimulate IL-4 secretion.
More recently, Chretien et al. [J. Immunol. Meth. 117:67 (1989)] reported that polyclonal rabbit antiserum to partially purified recombinant human IL-4 neutralized some of the biological activities of IL-4 in vitro. Monoclonal antibodies against synthetic polypeptides having amino acid sequences corresponding to residues 3-18, 31-46, 52-65 and 112-127 of mature human IL-4, however, failed to neutralize the bioactivity of IL-4 although they bound to the protein.
This invention provides polypeptides containing from about 5 to about 26 amino acid residues which have amino acid sequences corresponding to the sequence of amino acid residues 61 to 82 or 104 to 129 of human IL-4, or a subsequence thereof. Preferred polypeptides have the amino acid sequences
Lys-Asp-Thr-Arg-Cys (SEQ.ID.NO.: 45),
Thr-Ala-Gln-Gln-Phe-His-Arg-His (SEQ.ID.NO.: 21),
Lys-Asp-Thr-Arg-Cys-Leu-Gly-Ala-Thr-Ala-Gln-Gln-Phe-His-Arg-His-Lys-Gln-Leu-Ile-Arg-Phe (SEQ.ID.NO.: 7), and
Ala-Asn-Gln-Ser-Thr-Leu-Glu-Asn-Phe-Leu-Glu-Arg-Leu-Lys-Thr-Ile-Met-Arg-Glu-Lys-Tyr-Ser-Lys-Cys-Ser-Ser (SEQ.ID.NO.: 11).
The present invention further provides antibodies which inhibit the binding of human IL-4 to cellular receptors and specifically bind to such IL-4 and to polypeptides containing from about 5 to about 26 amino acid residues and having amino acid sequences corresponding to the sequence of amino acid residues 61 to 82 or 104 to 129 of human IL-4, or a subsequence thereof, which antibodies inhibit the binding of human IL-4 to cellular receptors.
This invention still further provides methods for making antibodies which specifically bind to and inhibit the binding of human IL-4 to cellular receptors, comprising administering to an animal a sufficient quantity of a polypeptide containing from about 5 to about 26 amino acid residues and having an amino acid sequence corresponding to the sequence of amino acid residues 61 to 82 or 104 to 129 of human IL-4, or a subsequence thereof, whereby the animal produces antibodies against the polypeptide which specifically bind to human IL-4 and inhibit the binding of human IL-4 to cellular receptors.
This invention still further provides anti-idiotypic antibodies against the above-mentioned antibodies. These antibodies presumably antagonize the biological activity of IL-4 by competing with IL-4 for binding to its cellular receptors.
This invention still further provides a method for inhibiting the binding of human IL-4 to cellular receptors, comprising contacting human IL-4 with an antibody which specifically binds to human IL-4 and to a polypeptide containing from about 5 to about 26 amino acid residues and having an amino acid sequence corresponding to the sequence of amino acid residues 61 to 82 or 104 to 129 of human IL-4, or a subsequence thereof, which antibody inhibits the binding of human IL-4 to cellular receptors.
This invention still further provides a method for inhibiting the binding of human IL-4 to cellular receptors, comprising contacting cells bearing receptors for human IL-4 with anti-idiotypic antibodies against an antibody which specifically binds to human IL-4 and to a polypeptide containing from about 5 to about 26 amino acid residues and having an amino acid sequence corresponding to the sequence of amino acid residues 61 to 82 or 104 to 129 of human IL-4, or a subsequence thereof, which anti-idiotypic antibodies inhibit the binding of human IL-4 to cellular receptors.
The antibody antagonists of the invention are useful in in vitro receptor binding studies to determine the mechanism of action of IL-4 and/or to identify agonists or other antagonists of IL-4. As noted above, they may also be useful for the treatment of allergies by decreasing IL-4-stimulated mast cell proliferation and IgE production.